"analyser" <cookiemon_29@yahoo.com.sg> wrote in message 
news:e7adnasQTY4fQ0rZnZ2dnUVZ_oWdnZ2d@giganews.com...
> Hi, I am doing this final year project in estimating the position of sound
> source. I have constructed two detection sets with each of four
> microphones. Each of these detection sets will yield a direction. Knowing
> that distance apart, we can localize the sound position in space.
>
> The problem now is I have to consider the direction of each detection set
> first. How do I calculate out the azimuth and inclination angles using the
> time delay?
>
With four microphones, you should be able to calculate the direction 
(bearing and elevation) to a sound source relative to some assumed zero 
direction, say a vector from the center of the array out through microphone 
#1.  By itself, this does not tell you anything about the orientation of the 
microphone array.

If you know this orientation, then you can get a direction to the sound 
source in the real world.  Then, given two oriented arrays at known 
positions, you should be able to determine the position of the sound source. 
There are several ways to determine the array orientation:
1. You can manually orient the array when you set it up ( set it flat on the 
ground oriented to the north for instance)
2.  You can attach some kind of computer readable compass and tilt sensor to 
each array.
3. You can start with the sound source in a known location and back out the 
array orientations.

BTW, based on having done this sort of thing for a living, you are probably 
better off working in the frequency domain and thinking in terms of phase 
differences rather than than time delays.

If you are going to test outside, don't forget some big wind screens

   Best wishes,
   --Phil Martel 

sheepshaggerx@yahoo.co.uk wrote:
> analyser wrote:
> > Hi, I am doing this final year project in estimating the position of sound
> > source. I have constructed two detection sets with each of four
> > microphones. Each of these detection sets will yield a direction. Knowing
> > that distance apart, we can localize the sound position in space.
> >
> > The problem now is I have to consider the direction of each detection set
> > first. How do I calculate out the azimuth and inclination angles using the
> > time delay?
>
> A similar problem is faced in GPS. Google for GPS estimation and you
> may find the answer.
>
> Baaaaa

This is NOT the way to proceed. There may be "similar" problems in GPS
(I am not sure about that though, but leave that for now), and whatever

solutions are used there can not be used for sound source localization.

In GPS, the source (the satellites) send information which contents
and encoding is known to the reciever. In source localization, one
usually
have to estimate both the presence and direction of a source.

As for the OP's task, there is a large body of literature on planar
arrays. It's not what I am most familiar with, but ther is a book by
Ziomek (don't remember the title) that ought to provide a good
starting point. 

Rune

analyser wrote:

   ...
>         I have constructed two detection sets with each of four
> microphones. ...

I don't think you mean that, and from the replies you got, neither do 
others. You seem to have meant "I have constructed two detection sets, 
each with four microphones."

BTW, at the price of a little more computation to get the beam 
directions, three microphones per set are enough.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

You might want to look into split-beam cross-correlation.  Try google.

In article <e7adnasQTY4fQ0rZnZ2dnUVZ_oWdnZ2d@giganews.com>, "analyser" 
<cookiemon_29@yahoo.com.sg> wrote:
>Hi, I am doing this final year project in estimating the position of sound
>source. I have constructed two detection sets with each of four
>microphones. Each of these detection sets will yield a direction. Knowing
>that distance apart, we can localize the sound position in space. 
>
>The problem now is I have to consider the direction of each detection set
>first. How do I calculate out the azimuth and inclination angles using the
>time delay?
>
>
>

analyser wrote:
> Hi, I am doing this final year project in estimating the position of sound
> source. I have constructed two detection sets with each of four
> microphones. Each of these detection sets will yield a direction. Knowing
> that distance apart, we can localize the sound position in space.
>
> The problem now is I have to consider the direction of each detection set
> first. How do I calculate out the azimuth and inclination angles using the
> time delay?

A similar problem is faced in GPS. Google for GPS estimation and you
may find the answer.

Baaaaa

Hi, I am doing this final year project in estimating the position of sound
source. I have constructed two detection sets with each of four
microphones. Each of these detection sets will yield a direction. Knowing
that distance apart, we can localize the sound position in space. 

The problem now is I have to consider the direction of each detection set
first. How do I calculate out the azimuth and inclination angles using the
time delay?